The 25-06 is more powerful than the 243. The 243 is based on the 308 and the 25 is based on the 30-06. The 25-06 hasa higher powder cap. with equal velocity and heavier bullets equals more energy. But you have to figure in type of bullet and what you are hunting. To many people only look at one aspect of the picture. that being said I own a 243 in rem. adl and probably the 3rd most accurate of any I have owned.